For the second problem.
the "ones" place is talking about the dollars (because a dollar is the complete number) and "tenths" is talking about every 10 cents of a dollar.
So, Rounding the salad and shrimps down and the rest of the things up(in the "ones"). We round this way because of the cents the prices have, when below 50 cents you round down when over 50 cents you round up. we get a new list.
salad = 4
shrimp = 7
hotdog= 14
cheesecake=7
cola= 2
total = $34
next, we round looking at the "tenths" and the "hundredths" will help us round.
and another list comes out
salad = 4.40
shrimp= 7.40
hotdog = 13.90
cheese cake = 7
cola= 2.20
total= $34.90
third problem
the correct way of writing this on your computer is as follows:
1) The population: 1.07 x 10^8
2) Species of Reptiles: 7.07 x 10^2
3) Mass of one grain of sand: 2.4 x 10^-3 grams
scientific notation is used to prevent writing things like this
1) The population: 1.07 x 10^8 = 1.07x100,000,000 = 107,000,000
2) Species of Reptiles: 7.07 x 10^2 = 7.07x100 = 707
3) Mass of one grain of sand: 2.4 x 10^-3 grams = 2.4 divided by 1000 = 0.0024
4 problem. well the simplest form is accomplished by dividing the top number and the bottom number by another number that both can be divided
88/100 both the 88 and the 100 can be divided by 2 = 44/50 again you can divide by 2 both 44 and 50 = 22/25 you can no longer divide both numbers by the same number so this is the simplest form.
all these fractions are equal to each other. 88/100 = 44/50 = 22/5. and you can also multiply the fractions. so 88/100 we multiply 88 and 100 by any number for example 4 = 352/400 = 88/100
same with the other fractions but i will just give you the simplest form
24/30 = 12/15
55/88 = 5/8 (divided by 11)
5th problem and last
^ = showing that the exponent is next
( ) = used to separate operations and when used next to other parenthesis, it means that it multiplies for example (2)(3)=6
*= multiplication same as 2x3= 6 2*3=6
211= 10^2 + 100 + 12 - 1^13
211= (2^2)*(3^2) + 8 +180+10
211= 11^2 + 8^2 + 4^2 + 10
211= 3^5 - 3^3 - 5
211= 211^0 + 210